PLACE

There’s more to the Northwest Territories’ Gahcho Kué diamond mine than precious gems

There’s more to the Northwest Territories’ Gahcho Kué diamond mine than precious gems

FFLY 280 KILOMETRES NORTHEAST of Yellowknife, and the small lakes and stunted spruce of the taiga give way to a 1,292-hectare gravel field. In two open pits that step more than 20 storeys into the Earth like dusty coliseums, ancient bedrock is blasted and loaded onto trucks bound for a clump of nearby buildings. There the ore is crushed, sorted and processed to extract more than six million carats of Canadian diamonds each year.

The Gahcho Kué diamond mine, owned by De Beers and Mountain Province Diamonds Inc., began production in 2017 and is the newest of three operating diamond mines in the Northwest Territories. Since the first diamond mine in Canada opened just 22 years ago, the country (and the Northwest Territories, in particular) has been prolific — Canada is now the third largest diamond producer by value and the second largest by carat in the world. And while Gahcho Kué made headlines for a 95-carat, cherry-sized stone pulled from its deposits in 2018, there’s far more than just diamonds there.

Gahcho Kué (“place of the big rabbits” in Dene Sųłiné) rests in the traditional territory of six Indigenous nations: the Deninu Kué First Nation, Lutsel K’e Dene First Nation, North Slave Métis Alliance, Northwest Territory Métis Nation, the Tłıc̨ hǫ Government and the Yellowknives Dene First Nation. It’s also just four kilometres from the newly established Thaidene Nëné National Park Reserve. In the winter, muskox, moose,

barren-ground caribou, foxes, wolves, wolverines, Arctic hares and ptarmigan speckle the flat, icy landscape. When the weather warms and the land bursts with berries, black bears, grizzly bears, geese, ducks and small birds come to feast, while lakes teem with trout and northern pike.

Traditional-knowledge monitors immerse themselves in this landscape for two weeks nearly every month to carefully measure the mine’s impacts on wildlife and the people who depend on it. Stationed just north of the mine site, in a white cabin overlooking Fletcher Lake, these monitors are part of the firstof-its-kind traditional knowledge program at the Ni Hadi Xa Alliance (Dene Sųłiné for “people watching the land together”), formed in 2014 as an agreement between the six nations and De Beers. Rosy Bjornson, environmental manager for the alliance, explains how these auditors take the pulse of the land.

“They jot down what they see, what they hear. If they harvest something, they have to tell us how it tastes and if they see anything different about it.”

Back at Gahcho Kué, Greg Dipple, a professor in the University of British Columbia’s department of Earth, ocean and atmospheric sciences, measures impacts of another kind. Dipple recently completed a trial of an innovative approach to capturing carbon emissions from the mine and storing them in solid mineral form, made possible in part by a $2-million grant from the federal government announced in July 2019.

Last August, as part of a series of field tests ending in March 2021, Dipple’s team captured carbon dioxide emissions in a quarter tonne of tailings, or waste rock, from the mining operations. The technology, which Dipple says is being used at mine sites around the world, could have the potential to make Gahcho Kué the world’s first carbon neutral mine, or better, but that will take years.

“If we were to be 100 per cent efficient, we could trap 10 times as much CO2 as is being emitted by the entire mining process. This opens up the idea that we could mine for the purpose of sequestering carbon,” says Dipple, adding that this scalable technology could be a tool to fight climate change.

“By the turn of the century, we’re going to have to be carbon negative as a society, and mining these kinds of rocks is one of the technologies being considered to reach that goal.”

Next year, Dipple plans to run the test again, with the goal of capturing more carbon. While his trials are still in their infancy, the technology is already worth its weight in diamonds.

An aerial view of part of the Gahcho Kué diamond mine (opposite) where the University of British Columbia is working with miners on an innovative carbon capturing project (above).